Water purification apparatus

ABSTRACT

A water purification apparatus having an inlet and an outlet, and at least one water purification means thereinbetween, wherein the outlet includes at least a first and second water release means, the first release means being operable at a first flow rate, and the second release means being operable at a second flow, is described. Preferably, at least one water release means is operable at a relatively slow flow rate of generally up to 0.1 litre per minute, and at least one other water release means is operable at a relatively fast flow rate of, for example, up to 2 litres per minute. The present water purification apparatus provides the operator with the ability to very accurately obtain an exact volume of water desired.

The present invention relates to the control of dispensing of water from water purification apparatus and units, particularly but not exclusively for laboratory water.

Water purification units for use in laboratories have been devised that remove levels of contaminants to very low levels. They typically contain a variety of technologies that remove particles, bacteria, ionic species and organic molecules. Water is recirculated within the unit to maintain the highest purity. When a user has required water he has typically opened a valve to dispense the amount of water required. A user will typically open the valve fully at first and partially close the valve as the amount of water dispensed approaches that required. This allows the user to make sure the amount of water does not exceed fill lines typically found on laboratory equipment.

U.S. Pat. No. 5,925,240 discloses an improved system of controlling the water output of the unit by varying the pump speed and/or the outlet valve's cross section in conjunction with a timer to give a desired amount of water. Both the pump and the valve can introduce an inaccuracy into the amount dispensed. Pump speed is typically controlled by reducing the voltage applied to the pump and correlation between this voltage and water output can vary depending upon inlet water pressure, temperature, back pressure and any gas hold up. Valve throughput can also be affected by pressure and temperature.

WO 01/27798 A discloses the use of a flow sensor to determine the amount of water dispensed by a deionization system and charge accordingly. It also includes a safety feature wherein the flow is halted if readings from the flow and pressure sensors indicate a missing/failed nozzle.

EP1134190A discloses a sensor fitted to a laboratory water purification unit which measures how much water has passed through the unit. A controller changes the pump speed between two speeds and opens a dispense valve to dispense an amount of water input into the units controller by the user.

It is an object of the present invention to provide an improved control of water dispensing from a small scale, e.g. laboratory, water purification apparatus or unit.

Thus, according to one aspect of the present invention, there is provided a water purification apparatus having an inlet and an outlet, and at least one water purification means thereinbetween, wherein the outlet includes at least a first release means and a second water release means, the first release means being operable at a first flow rate, and the second release means being operable at a second flow rate.

The outlet may include further water release means. One suitable release means is a valve.

Thus, the rate of release of water through the outlet can be controlled by a first flow rate, or a second flow rate, or a combination thereof; or further separate or conjoined flow rates if further water release means are used.

The flow rate of each water release means could be the same or different to the flow rate of every other water release means. Preferably, the first flow rate is different to the second flow rate.

In one embodiment of the present invention, the water release means operate in parallel. Two or more means could in addition or alternatively operate in series.

In another embodiment of the present invention, the water release means provide alternative flow paths for water through the outlet.

In yet a further embodiment of the present invention, each water release means is independently controllable from every other water release means.

Preferably, at least one water release means is operable at a relatively slow flow rate of generally up to 0.1 litre per minute, although this could of course be greater, for example up to 1.0 litre per minute, and at least one other water release means is operable at a relatively fast flow rate of, for example, up to 2 litres per minute.

Preferably, the operation and/or flow rate of at least one water release means is wholly or substantially dependant upon the operation and/or flow rate through at least one other water release means. More preferably, operation of a ‘faster’ flow rate water means is dependent upon operation of a relatively slow flow rate water release means.

In a further embodiment of the present invention, the water release means are operable manually and/or automatically, and either separately or independently.

In one arrangement, the apparatus includes a control means for controlling the outlet flow and/or flow rate through all the release means. For example operation of the control means opens a first, preferably ‘slow’ rate means, followed after a reasonable time period or flow by opening of a second ‘fast’ rate means. This arrangement could be reversed at or near the end of the desired outflow.

More preferably, the degree of operation of each water release means is dependent upon the amount or volume of water to be dispensed through the outlet.

Preferably, the apparatus includes one or more water pumps. The or each pump may be separately or integrally linked with one or more of the water release means, or at least to the means for controlling the water release through the outlet.

In a further embodiment of the present invention, the apparatus includes a recirculation system to provide recirculation around at least part of the apparatus of any water treated by the or one of the water purification means, but not immediately required by the outlet. Such a recirculation unit may include one or more pressure-sustaining means such as non-return valves to maintain outlet pressure.

The apparatus may include one or more alarm means, such as a visual and/or aural alert, to provide a signal for confirmation and/or feedback to the operator of the flow rate of the outlet, and/or the flow rate of one or more of the water release means.

The apparatus of the present invention may provide for the dispensing of water by any suitable arrangement based on time, volume, etc. Preferably, the apparatus of the present invention allows the operator to pre-set the volume of desired water to be dispensed, and the apparatus automatically operates the or each relevant water release means to provide a controlled (but usually variable) flow rate.

According to a second aspect of the present invention, there is provided a method for dispensing water from a water purification apparatus having an inlet, an outlet, and at least one water purification means thereinbetween, the outlet including at least two water release means, a first release means being operable at a first flow rate, and at least a second water release means being operable at a second flow rate,

-   -   wherein an operator organises the dispense of water from the         outlet through at least one of the water release means.

The present water purification apparatus provides the operator with the ability to very accurately obtain an exact volume of water desired.

Where the apparatus includes a control means, possibly with an associated control switch or button, the user can preferably set the volume or amount of water desired, and the apparatus automatically controls the release means, and any included pump(s), to provide said amount exactly. The control means can be pre-programmed to calculate the precise rate of flow required through the or each relevant release means.

Preferably, at least one of the water release means provides a relatively slow flow rate, particularly, but not exclusively, useable at the beginning and end of a water dispensing operation, whilst the second water release means provides water at a fast flow rate, and is generally more used during the middle of the operation for dispersement of water.

An embodiment of the present invention will now be described by way of example only and with reference to the accompanying FIG. 1, being a block-flow diagram of operation of an apparatus according to one embodiment of the present invention.

Referring to the drawing, a unit 2 operates with feedwater being drawn into the unit 2 via an inlet and a solenoid valve, V3. The water passes through a series of purification steps and past sensors for temperature and resistivity before being dispensed to an outlet via two release valves V1 and V2.

When water is not required, the pump recirculates the water to be purified through the purification steps maintaining it at the highest quality possible. A non return valve is included in the recirculation tubing to both prevent bypass of water to the outlet valves V1 and V2 without it passing through the purification steps, and also to provide a system pressure at which the water can be dispensed.

Water can be dispensed by turning a switch (not shown), which firstly, opens the low flow, trickle valve V2. This will dispense dropwise initially with an audible ‘click’ for each drop dispensed. As the switch is turned the drops and associated ‘clicks’ increase in rate, until the unit 2 dispenses a low continuous flow. On further turning, the unit opens the larger valve V1 increasing the dispense rate. On yet further turning the pump speed is increased causing water to be dispensed at a rate up to the maximum flowrate of for example two litres per minute. Pushing the switch closes the valves and reduces the pump speed. When dispensing, water is drawn into the unit via V3. When not dispensing, or when dispensing at a low rate, the unrequired water is recirculated around the loop.

When the operator wishes to dispense a fixed volume of purified water, he will input the amount, from, for example, 0.1 to 60 litres, via an operator interface on the unit 2 (not shown). When ready, the unit will open the valves V1 and V2 and increase pump speed as appropriate to the volume being dispensed. Water will be drawn into the unit via V3 and the flow sensor will transmit the rate of flow to the processor via a series of pulses. The processor will integrate the pulses and from this determine the amount of water dispensed. When the amount of water dispensed approaches the amount specified by the operator, the pump will slow down followed by valve V1 closing and finally valve V2 closing. The pump will continue to recirculate water around the loop.

The use of the two valves and variation in pump speed allows a more controlled outlet measure as the amount of water approaches that required. As the water reaches the fill point of the vessel being filled, then the user is still able to stop the dispense without excessive water dispense. The user may also be able to reduce the flow by turning the switch in the opposite direction so that a slow drip is dispensed as the water level approaches the fill line typically found on glassware. 

1-27. (canceled)
 28. A water purification apparatus having an inlet and an outlet, and at least one water purification means thereinbetween, wherein the outlet includes at least a first release means and a second water release means, the first release means being operable at a first flow rate, and the second release means being operable at a second flow rate.
 29. A water purification apparatus as claimed in claim 28, wherein the outlet includes further water release means.
 30. A water purification apparatus as claimed in claim 28, wherein the rate of release of water through the outlet is controlled by the first flow rate, or the second flow rate, or a combination thereof.
 31. A water purification apparatus as claimed in claim 28, wherein the first flow rate is different to the second flow rate.
 32. A water purification apparatus as claimed in claim 28, wherein the water release means operate in parallel.
 33. A water purification apparatus as claimed in claim 28, wherein the water release means provide alternative flow paths for water through the outlet.
 34. A water purification apparatus as claimed in claim 28, wherein each water release means is independently controllable from the or every other water release means.
 35. A water purification apparatus as claimed in claim 28, wherein at least one water release means is operable at a relatively slow flow rate and at least one other water release means is operable at a relatively fast flow rate.
 36. A water purification apparatus as claimed in claim 35, wherein the at least one water release means is operable at a relatively slow flow rate of up to 0.1 litres per minute, the at least one water release means is operable at a relatively fast flow rate of up to 2 litres per minute.
 37. A water purification apparatus as claimed in claim 28, wherein the operation and/or flow rate of at least one water release means is wholly or substantially dependent upon the operation and/or flow rate through at least one other water release means.
 38. A water purification apparatus as claimed in claim 35, wherein the operation of the relatively fast flow rate water means is dependent upon operation of the relatively slow flow rate water release means.
 39. A water purification apparatus as claimed in claim 28, wherein the apparatus includes one or more water pumps.
 40. A water purification apparatus as claimed in claim 39, wherein the or each pump is linked with one or more of the water release means.
 41. A water purification apparatus as claimed in claim 28, wherein the water release means are operable automatically.
 42. A water purification apparatus as claimed in claim 28, wherein the apparatus includes a control means for controlling the outlet flow and flow rate through all the release means.
 43. A water purification apparatus as claimed in claim 42, wherein the control means is pre-programmed to calculate the rate of flow through each release means.
 44. A water purification apparatus as claimed in claim 28, wherein the degree of operation of each water release means is dependent upon the amount or volume of water to be dispensed through the outlet.
 45. A water purification apparatus as claimed in claim 28, wherein the apparatus includes a recirculation system to provide recirculation around at least a part of the apparatus of any water treated by the or each water purification means.
 46. A water purification apparatus as claimed in claim 45, wherein the recirculation unit includes one or more pressure-sustaining means to maintain outlet pressure.
 47. A water purification apparatus as claimed in claim 28, wherein the apparatus includes one or more alarm means to provide a signal concerning the flow rate of the outlet and/or the flow rate of one or more of the water release means.
 48. A water purification apparatus as claimed in claim 28, adapted to provide a pre-set volume of water by automatic operation of one or each relevant water release means.
 49. A water purification apparatus as claimed in claim 28, wherein the release means are valves.
 50. A water purification apparatus as claimed in claim 28, wherein the first release means and second release means combine their flows prior to dispense of the flow from the outlet.
 51. A method for dispensing water from a water purification apparatus having an inlet and an outlet, and at least one water purification means thereinbetween, the outlet including at least a first release means and a second water release means, the first release means being operable at a first flow rate, and the second release means being operable at a second flow rate.
 52. A method of dispensing water as claimed in claim 51, wherein the dispense of water from the outlet is controlled through at least one of the water release means.
 53. A method of dispensing water as claimed in claim 51, wherein the apparatus includes a pump which is automatically controlled by a control means.
 54. A method of dispensing water as claimed in claim 51, wherein the water is provided by a first water release means having a relatively fast flow rate followed by a second water release means having a relatively slow flow rate.
 55. A method of dispensing water as claimed in claim 53, wherein the second water release means provides an initial relatively slow dispensement prior to the dispensement from the first release means.
 56. A method of dispensing water as claimed in claim 51, wherein the flow from the first release means and the flow from the second release means combine prior to the dispense of water from the outlet. 